This invention relates to inertial instrumentation, and more particularly to rebalance control networks for multiple inertial sensor instruments.
There are many inertial instruments in the prior art which utilize multiple inertial sensors. By way of example, the individual inertial sensors may be single degree of freedom (SDF) gyros, dynamically tuned (two degree of freedom) gyros, or accelerometers, or other known sensors. A typical multiple sensor instrument is an attitude reference assembly for a missile guidance system, which includes six single degree of freedom inertial sensors (three gyros and three accelerometers). In the conventional inertial instruments, each inertial sensor is embodied in a torque-to-balance loop. In addition to the inertial sensor, the loop includes, (1) a signal generator (such as a microsyn) for producing a signal representative of the sensor position, (2) a rebalance loop compensation network for modifying the signal generator output signal in accordance with desired performance characteristics, and (3) a torquer which is responsive to the modified signal generator output signal to rebalance the inertial sensor.
Typically, each inertial sensor in the instrument and its associated rebalance network includes all of the above-noted elements to form a corresponding plurality of full rebalance networks. For the rebalance loop bandwidths that are typically used, the multiplicity of circuit elements in the loop networks is relatively inefficient in terms of cost, weight, and volume, the latter factors being particularly important in terms of payload for missile applications.
Accordingly, it is an object of the present invention to provide a multiple sensor inertial instrument having a single time-shared rebalance loop network.